Method and apparatus for efficiently transmitting small amounts of data in wireless communication systems

ABSTRACT

According to one embodiment of the present disclosure, the method by means of which a mobility management entity (MME) determines the communication mode of a terminal in a communication system includes the steps of: receiving, from the terminal, an access request including information on the position of the terminal; transmitting a message to a home subscriber server (HSS) on the basis of the received access request; receiving, from the HSS, specific position information for setting a first mode; comparing the information on the position of the terminal with the specific position information; and determining the communication mode of the terminal according to the result of the comparison. According to the present disclosure, the frequent transmission of small amounts of data can be supported in an efficient manner.

CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM OF PRIORITY

This application is a continuation of U.S. patent application Ser. No.16/102,566 filed on Aug. 13, 2018, which is a continuation of U.S.patent application Ser. No. 14/377,150 filed on Aug. 6, 2014 now U.S.Pat. No. 10,051,458 issued on Aug. 14, 2018, which is a 371 ofInternational Patent Application No. PCT/KR2013/000303 filed on Jan. 15,2013, which claims priority to U.S. Provisional Patent Application No.61/595,646 filed on Feb. 6, 2012 and Korean Patent Application No.10-2012-0075216 filed on Jul. 10, 2012, the disclosures of which areherein incorporated by reference in their entirety.

BACKGROUND 1. Field

The present disclosure relates to a wireless communication system and,more particularly, to a method of reducing a signaling load occurringdue to the frequent transmission of small data and to a method ofmaintaining a terminal in a connected state.

2. Description of Related Art

In a wireless communication system, a terminal is in a connected statein which radio resources have been assigned to the terminal when sendingand receiving data, and switches to an idle state in which the radioresources have been released after completing the transmission andreception of the data. The terminal in the idle state performs signalingfor being assigned radio resources in order to send and receive dataagain.

If a variety of kinds of terminal applications are frequently used atthe same time these days, a terminal frequently generates small data,such as keep-alive and state transition. In such a case, the terminalfrequently performs signaling for the assignment and release of radioresources and core network resources in order to send and receive data,which generates a signaling load on a network.

Furthermore, if a terminal frequently sends and receives small data, theterminal frequently repeats the connected state and the idle state. Thismakes a network repeatedly perform S1 connection and data radio bearerestablishment, that is, network resources between a base station and anMME, thus experiencing a load.

Accordingly, there is a need for a method of efficiently processing arepetitive and small amount of data.

Meanwhile, various types of data applications could have become executedin a terminal at the same time due to the introduction of a smart phone.For example, a chatting program, a web browser, and streaming playersmay send and receive data at the same time. In particular, manyapplications that periodically access a network and exchange small datahave occurred, and an example thereof includes a chatting program or apush service program. A variety of kinds of such applications may havedifferent data occurrence cycles. For example, in general, a chattingprogram or push service exchanges data once every 5 seconds, whereasthere may be a situation in which a web browser sends data once everyseveral minutes to several hours.

Today, in the case where a terminal has set up RRC connection with abase station, if the activity of a user, that is, data activity, is notpresent for a specific time, the base station releases the RRCconnection in order to prevent the waste of resources. That is, the basestation releases the RRC connection if the activity of the terminal isnot present until a timer value expires using an inactivity timer.Today, the value of the inactivity timer may be voluntarily set by thebase station. Accordingly, since information about a user, that is,information about an application operating on a terminal, is notconsidered, precise conditions for the terminal is not considered, whichmay result in the repetition of the frequent setup and release of RRCconnection.

SUMMARY

The present disclosure has been made in order to solve the aboveproblems, and relates to a method of reducing a signaling load occurringdue to the frequent transmission of small data and to a method ofmaintaining a terminal in a connected state.

Furthermore, the present disclosure has been made in order to solve theabove problems, and relates to a method of controlling the time whenconnection between a terminal and a base station is maintained dependingon the characteristics of a user.

In order to achieve the objects, a method in a Mobility ManagementEntity (MME) determining communication mode of User Equipment (UE) in acommunication system in accordance with an embodiment of the presentdisclosure includes operations of receiving an access request comprisinginformation about the location of the UE; receiving information aboutspecific locations of the UE from a Home Subscriber Server (HSS) basedon the received access request; comparing the information about thelocation of the UE with the information about the specific locations;and determining the communication mode of the UE based on a result ofthe comparison.

An MME apparatus determining communication mode of UE in a communicationsystem in accordance with another embodiment of the present disclosureincludes a transceiver receiving an access request, includinginformation about the location of the UE, from the UE, sending a messageto an HSS based on the received access request, and receivinginformation about specific locations for configuring a first mode fromthe HSS; and a control unit comparing the information about the locationof the UE with the information about the specific locations anddetermining the communication mode of the UE based on a result of thecomparison.

A method in an MME determining communication mode of UE in accordancewith another embodiment of the present disclosure includes operations ofreceiving an access request transmitted by the UE; sending a locationupdate request to an HSS based on the received access request; receivinginformation about the state of the UE from the HSS; and transferringfirst information, including the received information about the state ofthe UE, to an eNodeB (eNB).

A method in an eNB determining communication mode of UE in accordancewith another embodiment of the present disclosure includes operations ofreceiving information about the state of the UE from an MME; configuringthe communication mode of the UE based on the received information aboutthe state of the UE; and sending first information, including theconfigured communication mode of the UE, to the UE.

A method in an MME determining a change of communication mode of UE inaccordance with another embodiment of the present disclosure includesoperations of receiving a bearer resource change request from the UE;sending a bearer resource command based on the received bearer resourcechange request; receiving information related to a bearer assigned tothe UE; and sending one or more of a bearer setup request and a sessionmanagement request to an eNB based on a request that generates thereceived bearer.

A method in an eNB determining a change of communication mode of UE inaccordance with yet another embodiment of the present disclosureincludes operations of receiving one or more of a bearer setup requestand a session management request from an MME; configuring the connectionmode of the UE based on information including the received requests; andsending information related to the configured mode to the UE.

In accordance with the present disclosure, the frequent transmission ofsmall data can be efficiently supported.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating the configuration of an EPS inaccordance with an embodiment of the present disclosure.

FIG. 2 is a diagram illustrating a scheme for configuring UE in smalldata management mode when the UE according to an embodiment accesses anetwork in order to be provided with service.

FIG. 3 is a diagram illustrating a scheme for configuring correspondingUE in small data management mode when the UE according to an embodimentaccesses a network in order to be provided with service.

FIG. 4 is a diagram illustrating a scheme for configuring correspondingUE in small data management mode when the UE according to an embodimentaccesses a network in order to be provided with service.

FIGS. 5A and 5B are diagrams illustrating that an MME or eNB accordingto an embodiment performs a change from small data management mode toconnected mode.

FIGS. 6A and 6B are diagram illustrating that an MME or eNB according toan embodiment perform a change from small data management mode toconnected mode.

FIG. 7 is a diagram illustrating that a PGW according to an embodimenttransfers mode change information to an MME or an eNB using a newmessage proposed by the present disclosure.

FIG. 8 is a diagram illustrating the case where a UE ContextModification Request message is used according to an embodiment.

FIG. 9 is a diagram illustrating a process of transmitting and receivingdata between a PGW1, a PGW2, an MME, and UE according to an embodimentof the present disclosure.

FIG. 10 is a diagram illustrating that UE according to an embodiment isset in small data management mode.

FIG. 11 is a diagram illustrating a process of taking locationinformation into consideration when UE according to an embodiment is setin small data management mode.

FIG. 12 is a diagram illustrating that UE according to anotherembodiment is set in small data management mode.

FIG. 13 is a diagram illustrating the flow of signals for controlling anRRC connection time according to an embodiment.

FIG. 14 is a diagram illustrating a method of setting an inactivity timebetween UE and the node of an RAN according to an embodiment.

FIG. 15 is a diagram illustrating a method of setting an inactivity timebetween UE and a node of an RAN according to another embodiment.

FIG. 16 is a diagram illustrating a method of setting an inactivity timebetween a node of a core network and a node of an RAN according to anembodiment.

FIG. 17 is a diagram illustrating a method of setting an inactivitytimer by taking into consideration the traffic characteristic of aservice application of UE according to an embodiment.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure are described indetail with reference to the accompanying drawings.

Preferred embodiments of the present disclosure are described in detailbelow with reference to the accompanying drawings. In this case, adetailed description of known functions or constructions that may makethe gist of the present disclosure vague is omitted.

Furthermore, in describing the embodiments of the present disclosure indetail, an Evolved Packet System (EPS) will be a major target, but themain gist of the present disclosure may be applied to othercommunication systems having a similar technical background with aslight modification within the scope that does not greatly depart fromthe scope of the present disclosure. This is possible by those skilledin the art to which the present disclosure pertains.

FIG. 1 is a block diagram illustrating the configuration of an EPS inaccordance with an embodiment of the present disclosure.

FIG. 1 illustrates only entities that belong to entities forming the EPSand that are related to an embodiment, and additional entities that arenot illustrated may be present in the EPS. Furthermore, a description ofthe following entities is given for only some related to the presentdisclosure, and additional functions may be included.

Referring to FIG. 1, User Equipment (UE) 100 is indicative of aterminal. An eNB 102 is an entity that controls radio resources and isconnected to the UE 100 through a radio channel. An MME is a MobilityManagement Entity 108. The MME manages the UE 100 in idle mode, and iscapable of performing functions related to the roaming andauthentication of the UE.

Furthermore, the MME 108 processes bearer signals generated by the UE100. An HSS is a Home Subscriber Server 110. The HSS stores subscriptioninformation about each UE 100, and transfers information related to theUE 100 to the MME 108 when the UE 100 accesses a network so that the MME108 uses the information to control the UE 100.

A serving gateway (SGW) 104 manages the user bearer of the UE, andnotifies the MME 108 of the arrival of data when the data reaches the UE100. The PGW 106 receives data to be delivered to the UE 100 from aservice network, or receives data to be delivered to a service networkfrom the UE 100. Furthermore, the PGW 106 has a policy for processingdata.

In the EPS, the UE 100 establishes a radio bearer with the eNB 102 inorder to send and receive data, and the eNB 102 and the MME 108 performcontext setup and establish S1 connection. When specific conditions aresatisfied after the transmission and reception of data are completed,the MME 108 or the eNB 102 release eNB context. This includes that Siconnection is immediately released. Furthermore, the eNB 102 performsRRC connection release from the UE 100 so that the UE 100 shifts to anidle state.

Each of the UE 100, the eNB 102, the SGW 104, the PGW 106, the MME 108,the HSS 110, and a PDN 112 in accordance with an embodiment of thepresent disclosure may include a transceiver capable of exchanging datawith other elements and a control unit capable of controlling theoperation of each of the elements including the transceivers.

In contents to be described later, a network may include the elements ofan EPS other than the UE 100, and may also be represented as a net.

In an embodiment, there is proposed a method for reducing a signalingload occurring due to the frequent transmission of small data.

First, an embodiment proposes a scheme for maintaining the UE 100, nothaving ongoing data, in connected mode. Through such a method, the shiftof a UE state that occurs when the UE 100 frequently sends and receivessmall data can be minimized.

Next, the present disclosure proposes a scheme for minimizing frequencyof mobility-related operations that are performed by the UE 100 inconnected mode that sends and receives small data with respect to thenetwork. The consumption of the battery can be minimized because the UEremains in connected mode by minimizing frequency of mobility-relatedoperations.

In an embodiment, small data management mode in which the UE 100 ismanaged in the network may be defined. In this case, small data mayinclude a low data rate at which the UE 100 sends and receives akeep-alive message or a state transition message and delay-tolerantbackground data

Small data management mode is mode in which the UE 100 is sending andreceiving small data or the UE 100 is connected, but may be mode inwhich the network manages the UE 100 if there is no data transmitted andreceived.

Small data management mode may be determined by the network.

In an embodiment, when the UE 100 enters small data management mode, thenetwork controls a state value within the UE 100 so that the UE 100performs a radio state measurement report with frequency smaller thanthat in connected mode, and sets an inactivity timer in order to controlthe time when the UE 100 shifts to idle mode.

Small data management mode proposed by the present disclosure maybasically include three types.

The three types include a mode decision, a mode configuration, and amode change.

The mode decision may include determining whether or not the networkconfigures the UE 100 in small data management mode when the UE 100accesses the network.

The mode configuration includes that the network controls theconfiguration of the UE so that the UE enters small data management modeor enters connected mode and performs the configurations of networkentities.

The mode change includes that the network changes the UE from small datamanagement mode to connected mode so that the UE 100 sends and receivesnormal data. The normal data may include one or more of voice and videodata transmitted and received by the UE.

Furthermore, the mode change includes a change from connected mode tosmall data management mode or idle mode. Furthermore, the mode changemay include a change from idle mode to small data management mode.

In the mode decision, when the UE 100 accesses the network, the networkmay determine whether or not to configure the UE 100 in small datamanagement mode.

An embodiment proposes a method of determining, by the network,configuring the UE 100 in small data management mode.

The method proposed by the embodiment may include:

1) a method of complying with subscription data stored in the HSS 110,

2) a method of selecting, by the MME 108, the UE 100 to which small datamanagement mode will be applied with reference to subscription datastored in the HSS 110,

3) a method of referring to, by the eNB 102, subscription data stored inthe HSS 110 or selecting the UE 100 to which small data management modewill be applied depending on network conditions, and

4) a method of applying, by the MME, small data management mode to UEdepending on the mobility of the corresponding UE.

FIG. 2 is a diagram illustrating a scheme for configuring UE 201 insmall data management mode in accordance with subscription data storedin an HSS 206 when the UE according to an embodiment accesses a networkin order to be provided with service.

Referring to FIG. 2, the UE 201 sends an access request message to anMME 203 in order to access the network, and the MME 203 receivessubscription information from the HSS 206 and transfers the receivedsubscription information to an eNB 202. After performing a modeconfiguration, the eNB 202 transfers information about the configurationto the UE 201. After connection is completed, the eNB 202 and the MME203 manage the UE in small data management mode.

At operation 210, the UE 201 may send an Attach Request message to theeNB 202.

At operation 215, the eNB 202 may transfer the received Attach Requestmessage to the MME 203.

At operation 220, the MME 203 may send an Update Location Request to theHSS 206 based on the received Attach Request message.

At operation 225, the HSS 206 may send an Update Location Ack to the MME203 based on the received Update Location Request so that the UE 201 isUE in which small data management mode needs to be configured.

Information including whether or not the UE 201 needs to be configuredin small data management mode may be included in the Update Location Ackmessage as a new parameter or may be included in part of UE subscriptiondata and may be transmitted. In an embodiment, Small Data Management(SDM) mode may include both the aforementioned two methods.

At operation 230, the MME 203 may establish the PDN connection of the UE201 by performing session creation with a PGW 205.

At operation 235, the MME 203 may notify the eNB 202 that the UE 201 isin SDM mode through one or more of Initial Context Setup Request andAttach Accept messages. What the MME 203 notifies the eNB 202 that theUE 201 is in SDM mode may be included in one or more of the ContentSetup Request and Attach Accept messages as a new parameter or may beincluded in part of UE subscription data and may be transmitted. SDMmode may include both the aforementioned two methods.

At operation 240, the eNB 202 may perform a mode configuration based onSDM mode information received at operation 235.

At operation 245, the eNB 202 sends information about mode set atoperation 240 to the UE 201. The configured mode information may betransmitted to the UE 201 through an RRC connection reconfigurationmessage.

At operation 250 to operation 270, the UE 201, the eNB 202, and the MME203 may perform the remaining Attach process.

FIG. 3 is a diagram illustrating a scheme in which when UE 301 accordingto an embodiment accesses a network in order to be provided withservice, an MME 303 selects UE to which SDM mode will be applied withreference to subscription data stored in an HSS 306 and configures thecorresponding UE in SDM mode.

The UE 301 sends an access request message to the MME 303 in order toaccess the network, and the MME 303 receives subscription informationfrom the HSS 306. The subscription data includes whether or not to allowthe user of the corresponding UE 301 configures the corresponding UE 301in SDM mode. Alternatively, the subscription data may include whether ornot a service provider wants to configure corresponding UE in SDM mode.The MME 303 determines whether or not to configure the corresponding UE301 in SDM mode with reference to the information.

The MME 303 transfers information indicative that the UE is in SDM modeto an eNB 302. After performing a mode configuration, the eNB 302transfers configuration information to the UE.

At operation 310, the UE 301 may send an Attach Request message to theeNB 302.

At operation 315, the eNB 302 may transfer the received Attach Requestmessage to the MME 303.

At operation 320, the MME 303 may send an Update Location Requestmessage to the HSS 306 based on the received Attach Request message.

At operation 325, the HSS 306 may send an Update Location Ack to the MME303 based on the received Update Location Request message in order tonotify that the UE 301 is UE in which SDM mode needs to be configured.

Information including whether the UE 301 needs to be configured in SDMmode may be included in the Update Location Ack message as a newParameter or may be included in part of UE subscription data and may betransmitted. In an embodiment, SDM mode may include both theaforementioned two methods.

At operation 330, the MME 303 may establish the PDN connection of the UE301 by performing session creation with a PGW 305.

At operation 335, the MME 303 may determine whether or not to configurethe corresponding UE 301 in SDM mode based on one or more of the piecesof information received at operation 325 and operation 330.

At operation 340, the MME 303 may notify the eNB 302 that the UE 301 isin SDM mode through one or more of Initial Context Setup Request andAttach Accept messages. What the MME 303 notifies the eNB 302 that theUE 301 is in SDM mode may be included in one or more of the ContentSetup Request and Attach Accept messages as a new parameter or may beincluded in part of the UE subscription data and may be transmitted. SDMmode may include both the aforementioned two methods.

At operation 345, the eNB 302 may perform a mode configuration based onSDM mode information received at operation 340.

At operation 350, the eNB 302 sends information about mode configured atoperation 345 to the UE 301. The configured mode information may betransmitted to the UE 301 through an RRC connection reconfigurationmessage.

At operation 355 to operation 375, the UE 301, the eNB 302, and the MME303 may perform the remaining Attach process.

FIG. 4 is a diagram illustrating that an eNB 402 according to anembodiment determines and configures UE to which SDM mode will beapplied.

FIG. 4 is a diagram illustrating a scheme in which when UE 401 accessesa network in order to be provided with service, the eNB 402 selects theUE 401 to which SDM mode will be applied with reference to subscriptiondata stored in an HSS 406 and configures the corresponding UE 401 in SDMmode.

The eNB 402 determines whether or not to configure the corresponding UE401 in SDM mode based on network conditions or based on informationincluded in subscription data received from an MME 403.

At operation 410, the UE 401 may send an Attach Request message to theeNB 402.

At operation 415, the eNB 402 may transfer the received Attach Requestmessage to the MME 403.

At operation 420, the MME 403 may send an Update Location Requestmessage to the HSS 406 based on the received Attach Request message.

At operation 425, the HSS 406 may send an Update Location Ack to the MME403 based on the received Update Location Request message in order to beindicative that the UE 401 is UE in which SDM mode needs to beconfigured.

Information including whether or not the UE 401 needs to be configuredin SDM mode may be included in the Update Location Ack message as a newparameter or may be included in part of the UE subscription data and maybe transmitted. In an embodiment, SDM mode may include both theaforementioned two methods.

At operation 430, the MME 403 may establish the PDN connection of the UE401 by performing session creation with a PGW 405.

At operation 435, the MME 403 may notify the eNB 402 that the UE 401 isin SDM mode through one or more of Initial Context Setup Request andAttach Accept messages. What the MME 403 notifies the eNB 402 that theUE 401 is in SDM mode may be included in one or more of the ContentSetup Request and Attach Accept messages as a new parameter or may beincluded in part of the UE subscription data and may be transmitted. SDMmode may include both the aforementioned two methods.

At operation 440, the eNB 402 may determine whether or not to configurethe corresponding UE 401 in SDM mode based on the information receivedat operation 435.

At operation 445, the eNB 302 may perform a mode configuration based oninformation determined at operation 440.

At operation 450, the eNB 402 sends information about mode configured atoperation 445 to the UE 401. The configured mode information may betransmitted to the UE 401 through an RRC connection reconfigurationmessage.

At operation 455 to operation 480, the UE 401, the eNB 402, and the MME403 may perform the remaining Attach process.

After completing the Attach process, the UE may operate in SDM modehaving a default bearer.

If the UE configured in SDM mode through the embodiments 1), 2), and 3)perform handover, information indicative that the UE has been configuredin SDM mode may be transferred from a source network to a targetnetwork.

In an embodiment, S1-based handover in which an MME is changed isdescribed as an example below. A source MME may transfer information,including that UE has been configured in SDM mode, to a target MME. Thetarget MME may transfer the information from the source MME to a targeteNB. The target eNB performs an SDM mode configuration, and transfersthe configuration to the target MME. The target MME may transfer theconfiguration, received from the target eNB, to the UE through thesource MME and a source eNB. The information indicative that the UE hasbeen configured in SDM mode and the SDM mode configuration may beincluded in messages, exchanged when handover is performed, in the formof UE context. Furthermore, according to an embodiment, the informationindicative that the UE has been configured in SDM mode and the SDM modeconfiguration may be transferred from the source eNB to the source MME.

In another embodiment of the present disclosure, an MME determineswhether or not to apply SDM mode depending on the mobility of UE andconfigures SDM mode.

For example, when the UE enters a specific area, such as a home or anoffice, a probability that handover may occur may be suddenly reducedbecause mobility is sharply reduced. In such a case, optimum conditionsin which SDM mode is applied may be achieved because a handover loadoccurring when the UE remains in connected mode for a long time isreduced.

In the present embodiment, the MME may determine whether or not to applySDM mode depending on the mobility of the UE. For example, if the UEmoves at high speed, the MME does not apply SDM mode. If the UE moves atlow speed, the MME applies SDM mode. Furthermore, if the UE is placed ina specific area determined to have small mobility, the MME may apply SDMmode.

In accordance with an embodiment of the present disclosure, thesubscription data may include information related to an area in whichthe mobility of the UE has been sharply reduced and to which SDM modemay be applied. Alternatively, information about the mobility of the UEmeasured by the network may be included in the subscription data.

Table 1 is a diagram illustrating an example of the subscription dataincluded in the HSS according to an embodiment.

TABLE 1 Field Description Small data area Indicates the area/location(e.g., a TA, an RA, a cell) for long connected mode UE mobilityIndicates the mobility of the UE (e.g., MDT information)

The HSS may include a ‘small data area’ field proposed by the presentdisclosure. The small data area includes an area/location to which SDMmode is preferably applied. The area may have any form that includes oneor more of a tracking area, a routing area, a cell, a home, and anoffice. More specifically, if SDM mode is applied, the small data areamay be an area where a signaling load between an eNB and an MME may befurther reduced. Information about the small data area may have beenrecorded on the HSS based on a previously measured value. Furthermore,the HSS may include a ‘UE mobility’ field. The value of the UE mobilitymay include information about the mobility of the UE. According to anembodiment, a network may include mobility information including thespeed of the UE that has been collected through an MDT.

FIG. 11 is a diagram illustrating that an example in which an MME 1103determines whether or not to apply SDM mode depending on the mobility ofUE 1101 and configures SDM mode is described through an Attach processaccording to an embodiment.

Referring to FIG. 11, the UE 1101 may send an access request message tothe MME 1103 in order to access a network. The MME 1103 may receivedata, including the subscription information described with reference toTable 1, from an HSS 1106. The MME 1103 may check an area in which theUE 1101 is placed, and may determine whether or not to configure thecorresponding UE 1101 in SDM mode based on the received subscriptioninformation. The MME 1103 transfers information indicative that the UEis in SDM mode to an eNB 1102. After performing a mode configuration,the eNB 1102 transfers configuration information to the UE 1101.

More specifically, at operation 1110, the UE 1101 may send an AttachRequest message to the eNB 1102.

At operation 1115, the eNB 1102 may transfer the received Attach Requestmessage to the MME 1103.

At operation 1120, the MME 1103 may send an Update Location Requestmessage to the HSS 1106 based on the received Attach Request message.

At operation 1125, the HSS 106 may send an Update Location Ack to theMME 1103 based on the received Update Location Request. The UpdateLocation Ack may include one or more of an indicator indicating that theUE 1101 is UE in which SDM mode needs to be configured and informationrelated to a small data area in which it is easy to apply SDM mode tothe UE. More specifically, the small data area may be included insubscription data, and the subscription data may be transferred from theHSS 1106 to the MME 1103.

At operation 1130, the MME 1103 may establish the PDN connection of theUE 1101 by performing session creation with a PGW 1105.

At operation 1135, the MME 1103 may check whether or not the area wherethe UE 1101 is placed and that has been received through the AttachRequest message is included in the ‘small data area’ of the subscriptiondata received from the HSS 1106. If the area where the UE 1101 is placedis included in the ‘small data area’, the MME 1103 configures the UE1101 in SDM mode. If the area where the UE 1101 is placed is notincluded in the ‘small data area’, the MME 1103 may perform a normalAttach process. Alternatively, the MME 1103 may check information aboutthe mobility of the UE 1101 through ‘UE mobility’ within thesubscription data. If the UE 1101 has speed/mobility of a specificreference or lower, the MME 1103 configures the UE 1101 in SDM mode. Ifthe UE 1101 has speed/mobility of a specific reference or higher, theMME 1103 performs a normal Attach process. The specific reference may bea value set by a service provider, or may be included in thesubscription information.

Subsequent processes may be performed like the processes subsequent tooperation 340 of FIG. 3.

FIG. 12 is a diagram illustrating that an example in which an MMEdetermines whether or not to apply SDM mode depending on the mobility ofUE and configures SDM mode is described through an S1-based handoverprocess according to an embodiment.

If handover conditions are satisfied, a source eNB 1202 transfers ahandover request to an MME. The MME has received the subscriptioninformation, described with reference to Table 1, from an HSS through anAttach process, and has stored the received subscription information.The MME may check an area/location where UE moves, and may determinewhether or not to configure the corresponding UE 1201 in SDM mode basedon the subscription information. The MME may transfer informationindicative that the UE 1201 is in SDM mode to target eNB. Afterperforming a mode configuration, a target eNB transfers configurationinformation to the UE.

The embodiment of FIG. 12 has illustrated only the case of handover inwhich the MME is changed, but omitted a process with an SGW.

At operation 1210, the source eNB 1202 may determine to start relocationthrough S1. At operation 1215, the source eNB 1202 may send an HOrequired message to the source MME 1204. The source eNB 1202 may notifythe source MME 1204 that the UE 1201 requires handover through the HOrequired message.

At operation 1220, the source MME 1204 may transfer a forward relocationrequest message to a target MME 1205 in order to perform the handoverbased on the message received at operation 1215. The forward relocationrequest message may include information about the location where the UE1201 is not placed.

At operation 1225, the target MME 1205 may check whether or not the areawhere the UE 1201 is placed and that has been received from the sourceMME 1204 at operation 1220 is included in a ‘small data area’ within thesubscription data If the area where the UE 1201 is placed is included inthe ‘small data area’, the target MME 1205 configures the UE 1201 in SDMmode. If the area where the UE 1201 is placed is not included in the‘small data area’, the target MME 1205 may perform a normal handoverprocess. Alternatively, the target MME 1205 may determine whether or notto configure SDM mode through ‘UE mobility’ within the subscription dataThis is the same as the reference of the embodiment described withreference to FIG. 11.

At operation 1230, the target MME 1205 may determine to configure the UE1201 in SDM mode based on a result of the determination at operation1225.

At operation 1235, the target MME 1205 may transfer a message, includinginformation indicative that the UE 1201 has been configured in SDM mode,to a target eNB 1203.

At operation 1240, the target eNB 1203 may perform an SDM modeconfiguration.

At operation 1245, the target eNB 1203 may notify the target MME 1205that the UE 1201 has been configured in SDM mode through an HO requestack message. The HO request ack message may include information aboutthe mode configuration of the target eNB 1203.

At operation 1250, the target MME 1205 may send a forward relocationresponse message to the source MME 1204. The forward relocation responsemessage may include mode configuration information received at operation1245.

At operation 1255, the source MME 1204 may transfer an HO commandmessage to the source eNB 1202. The HO command message may include themode configuration information received at operation 1250.

At operation 1260, the source eNB 1202 may transfer the HO commandmessage to the UE 1201. The HO command message may include the modeconfiguration information received at operation 1255.

Subsequent processes may be performed like the aforementioned handoverprocesses.

It is to be noted that additional processes may be required for theattachment and handover of the UE in addition to the processes marked inFIGS. 2 to 4, 11, and 12. Furthermore, it is to be noted that differentmessages may be used other than the messages proposed in the drawings ordifferent parameters may be used.

A method of performing a mode configuration according to an embodimentis described below with reference to FIG. 2.

The mode configuration includes that a network performs the internalconfigurations of network entities in order to set UE in SDM mode orconnected mode and controls a configuration value transferred to the UE.

In an embodiment, the eNB 102 may perform a mode configuration bysetting an SDM inactivity timer and/or setting a measurementconfiguration value and/or setting the DRX value of UE.

First, although ongoing data is not present, the eNB 102 may maintain aSmall Data Management (SDM) inactivity timer in order to maintain the UE100 in connected mode. The SDM inactivity timer may be a value changedfrom the value of an existing inactivity timer, or may be a parameterthat has been newly generated for SDM mode.

The SDM inactivity timer is indicative of the time when the eNB 102maintains the UE 100 of SDM mode in connected mode. The UE 100 mayremain in connected mode regardless of whether data has been transmittedor not until the SDM inactivity timer expires. That is, the eNB 102 doesnot perform 51 release, that is, network resources between the eNB 102and the MME 108.

In general, if the eNB wants to lengthily maintain the UE in connectedmode as proposed by the present disclosure, the SDM inactivity timer maybe set to be longer than that in connected mode. In general, if anexisting inactivity timer is used as the SDM inactivity timer, the valueof the existing inactivity timer may be set to be longer than that inconnected mode.

The SDM inactivity timer proposed by the present disclosure is apre-configured value that is identically set for the UE 100 in SDM mode,or includes a value that is differently set by the eNB 102 according toeach UE depending on network conditions.

The eNB sets a DRX value transferred to the UE. In accordance with anembodiment, the eNB separately has a DRX value for UE in SDM mode. Inaccordance with another embodiment, the DRX value may be received fromthe MME. In accordance with the DRX value, in general, the DRX value ofUE in SDM mode may be set to be longer than that in connected mode. Forexample, UE in SDM mode may use a DRX value that is used in idle modealthough the UE is in connected mode.

The eNB 102 sets a measurement configuration value transferred to theUE. In accordance with an embodiment, the eNB 102 separately has ameasurement configuration value for UE in SDM mode. In accordance withthe measurement configuration, for example, the interval at which the UE100 sends a measurement report may be longer than that in existingconnected mode, or a threshold value at which the UE 100 sends ameasurement report may be smaller than that in existing connected mode.

The measurement configuration may include a new parameter value or thevalue of an existing parameter within a MeasConfig IE within anRRCConnectionreconfiguration message in a modified form.

The value of the measurement configuration may be a value previously setby a service provider, or may be a value that is variably set by the eNB102 according to the network state. Furthermore, the value of themeasurement configuration may be identically set in all the eNBs 102within the network, or may be differently set in each eNB 102.Furthermore, the value of the measurement configuration may beidentically applied to all pieces of UE in SDM mode, or may bedifferently set and applied to each piece of the UE 100.

A mode change is described below with reference to FIG. 1.

First, a process of a change from SDM mode to connected mode isdescribed below.

If the UE 100 in SDM mode sends normal data or the UE 100 receives thenormal data, a network may change mode of the UE 100 into connectedmode.

An embodiment of the present disclosure proposes the following method asa method of performing a mode change.

1. First, a mode change may be performed using a message related tobearer resources requested by the UE 100, or

2. the network may detect normal data based on one or more of type andform of data transmitted and received by the UE 100. A mode change maybe performed based on the detection, or

3. a mode change may be performed when the UE deviates from a ‘smalldata area’ within subscription data.

1. A method of performing a mode change using a message related tobearer resources requested by the UE 100 is described below. If the UE100 wants to send normal data, the UE 100 uses a process or methoddefined in an existing standard. In brief, the UE sends a message thatrequests required bearer resources to the PGW 106 over a network.

The PGW 106 that has received the message requesting the bearerresources may instruct a new dedicated bearer to be generated if it isunable to provide the bearer resources requested by the UE 100 due tothe modification of an existing bearer. Furthermore, if the bearerresources requested by the UE 100 can be provided due to themodification of an existing bearer, the PGW 106 may instruct theresources of the existing bearer to be modified and used.

In an embodiment, information for changing mode of the UE 100 intoconnected mode may be obtained from a message that instructs a newbearer to be generated, or may be obtained from a parameter proposed byan embodiment in which the necessity of a mode change is indicative by amessage that instructs an existing bearer to be modified and used. Thecontents in which information for changing mode of the UE 100 intoconnected mode is obtained from a message that instructs a new bearer tobe generated are described with reference to FIGS. 5A and 5B.Furthermore, the contents in which the necessity of a mode change isindicative by a message that instructs an existing bearer to be modifiedand used are described with reference to FIGS. 6A and 6B.

FIGS. 5A and 5B are diagrams illustrating that an MME or an eNB obtainsmode change information from a message that instructs a new bearer to begenerated (from a PGW) and performs a change from SDM mode to connectedmode.

Referring to FIGS. 5A and 5B, in an embodiment, an MME 503 or an eNB 502may determine whether UE 501 requests normal data or the UE 501 is usingsmall data based on the number of bearers of the UE 501.

A mode decision may be made by the MME 503 or the eNB 502. If the MME503 makes a mode decision, Alt1 methods 528 and 546 may be used. If theeNB 502 makes a mode decision, Alt2 methods 534 and 550 may be used.

In an embodiment, it is assumed that the eNB 502 and the MME 503 alreadyknow that the corresponding UE 501 is in SDM mode (operation 512).

At operation 514, the UE 501 determines to send normal data

At operation 516, the UE 501 may send a Request Bearer ResourceModification message to the MME 503.

At operation 518 to operation 526, the MME 503 transfers a request,including the Request Bearer Resource Modification message received atoperation 516, to a PGW 505. The PGW 505 may generate a new bearer basedon data communication with a PCRF 506 and the request from the UE 501,and may notify the MME 503 of the generated new nearer through a CreateBearer Request. A process of generating the bearer complies with astandard process.

Alt1) 528, at operation 530, the MME 503 that has received the CreateBearer Request determines that the UE 501 wants to send the normal databased on the request of the new bearer from the UE 501 in SDM mode. TheMME 503 that has determined that the UE 501 sends the normal datadetermines to configure the UE in connected mode.

At operation 532, the MME 503 notifies the eNB 502 that the UE 501 hasbeen configured in connected mode. At operation 532, information that isused for the MME 503 to provide the notification to the eNB 502 may beincluded in a Bearer setup Request/Session management request message asa new parameter, or the MME 503 may notify the eNB 502 that the UE 501has been configured in connected mode by changing a value within anexisting parameter. A mode change illustrated in FIG. 5 may include boththe aforementioned two methods.

Alt2) 534, at operation 536, the MME 503 sends a Bearer setupRequest/Session management request message to the eNB 502 according toan existing standard process.

At operation 538, the eNB 502 that has received the message determinesthat the UE 501 wants to send the normal data based on the request ofthe new bearer from the UE 501 in SDM mode. The eNB 502 that hasdetermined that the UE 501 sends the normal data determines to configurethe UE in connected mode.

At operation 540, the eNB 502 may perform a connected mode configurationbased on the received or determined mode change information. The processmay include a normal configuration.

At operation 542, the eNB 502 sends information, including informationabout mode configured at operation 540, to the UE 501 through an RRCconnection reconfiguration message.

At operation 548 to operation 564, the UE 501 performs the remainingbearer creation process.

This requires an additional process in which the eNB 502 notifies theMME 503 that the UE 501 changes into connected mode only in the case ofan Alt2 550 in an existing standard process (operation 552).

In the process of providing the notification to the MME 503, informationindicative that the UE 501 has changed into connected mode may beincluded as a new parameter within a Bearer setup response message, oris possible by changing a value within an existing parameter. The UE inconnected mode indicated in FIGS. 5A and 5B refers to both theaforementioned two methods. Subsequent bearer creation processes maycomply with an existing standard process.

FIGS. 6A and 6B are diagrams illustrating that an MME 603 or an eNB 602obtains mode change information from a message that has been transmittedby a PGW 605 and that instructs a change of an existing bearer andperforms a change from SDM mode to connected mode.

Referring to FIGS. 6A and 6B, a mode decision may be made by the MME 603or the eNB 602. If the MME 603 makes a mode decision, Alt1 methods 628and 646 of FIGS. 6A and 6B are used. If the eNB 602 makes a modedecision, Alt2 methods 634 and 650 of FIGS. 6A and 6B are used.

In the case of the methods described in FIGS. 6A and 6B, the MME 603 orthe eNB 602 may receive additional information from the PGW 605according to an embodiment of the present disclosure because it isunable to know whether UE 601 requests normal data or the UE 601 isusing small data based on the number of bearers, and may determine amode change.

The difference between FIGS. 5 and 6 is that an Update Bearer Requestmessage initiated at operation 624 is used because an existing bearer ismodified in order to send and receive normal data and the MME 603 or theeNB 602 receives additional information indicative that a bearer hasbeen modified from the PGW 605 in order to send and receive normal data.

The additional information may be included in the Update Bearer Requestmessage as a new parameter at operation 624, or is possible by changinga value within an existing parameter.

A bearer modification indicator refers to both the aforementioned twomethods indicated in FIG. 6.

In an embodiment, it is assumed that the eNB 602 and the MME 603 alreadyknow that the corresponding UE 601 is in SDM mode (operation 612).

At operation 614, the UE 601 determines to send normal data

At operation 616, the UE 601 may send a Request Bearer ResourceModification message to the MME 603.

At operation 618 to operation 626, the MME 603 transfers a request,including the Request Bearer Resource Modification message received atoperation 616, to the PGW 605. The PGW 605 may generate a new bearerbased on data communication with a PCRF 606 and the request from the UE601, and may notify the MME 603 of the generated new bearer through aCreate Bearer Request. A process of generating the bearer complies witha standard process.

Alt1) 628, at operation 630, the MME 603 that has received the CreateBearer Request including a bearer modification indicator determines thatthe UE 601 wants to send the normal data based on the request of the newbearer from the UE 601 in SDM mode. The MME 603 that has determined thatthe UE 601 wants to send the normal data determines to configure the UEin connected mode.

At operation 632, the MME 603 notifies the eNB 602 that the UE 601 hasbeen configure3d in connected mode. At operation 632, information usedfor the MME 603 to provide the notification to the eNB 602 may beincluded in a Bearer setup Request/Session management request message asa new parameter, or the MME 603 may notify the eNB 602 that the UE 601has been configure3d in connected mode by changing a value within anexisting parameter. A mode change indicated in FIGS. 6A and 6B mayinclude both the aforementioned two methods.

Alt2) 634, at operation 636, the MME 603 sends the Bearer setupRequest/Session management request message to the eNB 602 according toan existing standard process.

At operation 638, the eNB 602 that has received the message determinesthat the UE 601 wants to send the normal data based on the request ofthe new bearer from the UE 601 in SDM mode. The eNB 602 that hasdetermined that the UE 601 wants to send the normal data determines toconfigure the UE in connected mode.

At operation 640, the eNB 602 may perform a connected mode configurationbased on the received or determined mode change information. The processmay include a normal configuration.

At operation 642, the eNB 602 sends information, including informationabout mode configured at operation 640, to the UE 601 through an RRCconnection reconfiguration message. At operation 648 to operation 664,the UE 601 performs the remaining bearer modification processes.

This requires an additional process of notifying, by the eNB 602, theMME 603 that the UE 601 has changed into connected mode only in the caseof the Alt2 method 650 in an existing standard process.

In the process of providing the notification to the MME 603, informationindicative that the UE 601 has changed into connected mode may beincluded in a bearer setup response message as a new parameter, or ispossible by changing a value within an existing parameter. The UE inconnected mode indicated in FIGS. 6A and 6B refers to both theaforementioned two methods. Subsequent bearer modification processes maycomply with an existing standard process.

2. A technology in which a network detects the transmission of normaldata based on the type or form of data transmitted and received by theUE 100 is described below. In accordance with the present disclosure, ifthe UE 100 wants to send normal data, the UE sends the normal datathrough an already included default bearer. After a specific time, thePGW 106 or a Traffic Detection Function (TDF) detects that thecorresponding data is the normal data. In other words, the PGW 106 orthe TDF detects that the corresponding data is not small data In thepresent disclosure, a method of detecting, by the PGW 106 or the TDF,small data is described. The detection of normal data becomes aware bydetecting that corresponding data is not small data. The specific timeduring which the PGW 106 or the TDF detects that corresponding data isnot small data (i.e., the corresponding data is normal data) may complywith a service provider policy, or may be selectively set depending onnetwork conditions.

A method of detecting, by the PGW 106 or the TDF, small data basicallyincludes two methods.

The first method is to use a De-Packet Inspection (DPI) function, andthe second method is to use a packet filter.

The first method using the DPI function is described below.

1) The method of detecting, by the PGW 106, small data using the DPIfunction may include the following operations.

The PGW 106 receives an Application Detection Control (ADC) rule fordetecting small data from the PCRF and installs the received ADC rule.Alternatively, the PGW 106 may detect small data according to apre-configured rule.

In an embodiment, the PGW 106 detects small data according to a ruleusing the DPI function.

2) The method of detecting, by the TDF, small data using the DPIfunction may include the following operations.

The TDF 106 receives the ADC rule for detecting small data from the PCRFand installs the received ADC rule. Alternatively, the TDF 106 maydetect small data according to a rule pre-configured in the TDF. Ifsmall data is detected through the TDF, the TDF transfers the results ofthe detection to the PCRF, and the PGW 106 receives detectioninformation from the PCRF.

A method of receiving, by the PGW 106, the detection information fromthe PCRF may include a pull method of asking, by the PGW 106, the PCRFor a push method of transferring, by the PCRF, a request to the PGW 106.

The second method using a packet filter is described below.

A specific entity or a PCRF within a service provider network mayconfigure a packet filter for detecting small data using an applicationserver address and port information with which an application serveroutside the service provider network has been registered. The PCRF mayconfigure the packet filter in an ADC rule form, and may transfer theconfigured ADC rule to the PGW 106 or the TDF. The PGW 106 or the TDFinstalls the received ADC rule. Alternatively, the PCRF may transfer thepacket filter to the PGW or the TDF. Alternatively, the packet filterreceived by the PGW may be transferred to the SGW. The SGW may detectsmall data using the received packet filter.

The PGW 106 may transfer information, detected using the method, to theMME 108 or the eNB 102. The information may be used to change the UE 100into connected mode.

3. A technology for performing a mode change when UE deviates from a‘small data area’ within subscription data is described below.

If UE performs handover, an MME checks whether the location to which theUE moves is included in a ‘small data area’. If the location to whichthe UE moves is not included in the small data area, the MME may changethe UE into connected mode.

FIG. 7 is a diagram illustrating that a PGW transfers mode changeinformation to an MME 703 or an eNB 702 using a new message proposed bythe present disclosure.

Referring to FIG. 7, a mode decision may be made by the MME 703 or theeNB 702. If the MME 703 makes a mode decision, Alt1 methods 728 and 746of FIG. 7 are used. If the eNB 702 makes a mode decision, Alt2 methods734 and 750 of FIG. 7 are used.

At operation 712, the eNB 702 and the MME 703 already know thatcorresponding UE 701 is in SDM mode.

At operation 714, the UE 701 determines to send normal data

At operation 716, the UE 701 sends the normal data through a defaultbearer.

At operation 718, the PGW 705 detects the normal data transmitted by theUE 701.

At operation 720, the PGW 705 may notify an SGW 704 that the UE 701 hasstarted sending and receiving the normal data through Notify normaldata, that is, a GTP-C message proposed by an embodiment.

At operation 722, the SGW 704 may send the received Notify normal datato the MME 703.

At operation 724, the MME 703 may send a Notify normal data ackindicative that the successful reception of the Notify normal data tothe SGW 704. At operation 726, the SGW 704 may send the Notify normaldata ack to a PGW 705.

Alt1) 728, at operation 730, the MME 703 that has received the requestmay determine to configure the UE in connected mode.

At operation 732, the MME 703 may notify the eNB 702 that the UE 701 hasbeen configured in connected mode through a Notify normal data message,that is, an S1-AP message proposed by an embodiment.

Alt2) 734, at operation 736, the MME 703 sends a Mode change requestmessage, that is, an S1-AP message proposed by an embodiment, to the eNB702.

At operation 738, the eNB 702 may determine to configure the UE 701 inconnected mode based on the received Mode change request message.

At operation 740, the eNB 702 may perform a connected mode configurationbased on the received mode change information.

At operation 742, the eNB 702 may send information about mode configuredat operation 740 to the UE 701 through an RRC connection reconfigurationmessage.

At operation 744, the UE 701 that has received the RRC connectionreconfiguration message may send an RRC connection reconfigurationcomplete message to the eNB 702.

Alt1) 746, at operation 748, the eNB 702 may send a Mode change responsemessage, that is, an S1-AP message proposed by an embodiment, to the MME703.

Alt2) 750, at operation 752, the eNB 702 may send a Notify normal dataack message, that is, an S1-AP message proposed by an embodiment, to theMME 703.

In addition to the S1-AP message used in FIG. 7, an existing S1-APmessage may also be used to transfer mode change information.

FIG. 8 is a diagram illustrating the case where the UE ContextModification Request message, that is, the aforementioned existing S1-APmessage, is used.

Referring to FIG. 8, an MME 803 may include mode change information in aUE Context Modification Request message, that is, an S1-AP message,instead of Notify normal data, and may send the UE Context ModificationRequest message to an eNB 802. The information may be included in the UEContext Modification Request message as a new parameter, or is possibleby changing a value within an existing parameter.

A process of performing a change into connected mode, SDM mode, or idlemode is described below with reference to FIG. 1.

In accordance with an embodiment, the UE 100 that has completed thetransmission of normal data may shift to SDM mode, and the UE 100 mayshift to idle mode. Whether the UE 100 shifts to SDM mode or idle modemay be selectively determined by the configuration of a serviceprovider.

A method of performing, by the UE 100, a mode change into SDM mode issimilar to those described with reference to FIGS. 5A, 5B, 6A, 6B, 7,and 8. A network may detect SDM mode using a message related to bearerresources requested by the UE 100 or through the type/form of datatransmitted and received by the UE 100.

First, a method using the message related to bearer resources requestedby the UE 100 is described below. If the UE 100 completes thetransmission of normal data, the UE 100 uses a process/method defined inan existing standard. The UE 100 sends a message that requests bearerresources for the PGW 106 to a network.

In such a case, the bearer resources requested from the PGW 106 by theUE 100 have a value smaller than an existing value. The PGW 106 that hasreceived the message may modify an existing bearer into the bearerresources requested by the UE 100, or may instruct that a dedicatedbearer used to send the normal data be deleted.

In an embodiment, information for changing the UE 100 into SDM mode maybe obtained from a message instructing that a dedicated bearer bedeleted, or may be obtained from a parameter proposed by an embodimentin which the necessity of a mode change is indicative in a message thatinstructs an existing bearer be modified and used.

The aforementioned method is applied like the processes described withreference to FIGS. 5A, 5B, 6A, and 6B. The difference is that ifinformation for changing the UE 100 into SDM mode is obtained from themessage instructing that a dedicated bearer be deleted, the PGW 106sends a Delete Bearer Request to the MME 108. Furthermore, the eNB 102configures SDM mode.

The case where a network detects SDM mode through the type/form of datatransmitted and received by the UE 100 is described below. If the UE 100completes the transmission of normal data, the PGW 106 detects that theUE 100 has completed the transmission and reception of the normal data.The detection is possible through the PGW 106 or the TDF. The detectionmay mean the case where the PGW or the TDF detects small data or thecase where no data transmission and reception has been detected. The PGW106 transfers such information to the MME 108 or the eNB 102, and theinformation may be used to change the UE into SDM mode.

If the UE 100 includes a plurality of PDN connections with a pluralityof the PGWs 106, the transmission of normal data in a single PDNconnection has been terminated, but the transmission and reception ofnormal data in other PDN connections may be in progress. That is, theMME 108 and the eNB 102 need to check whether mode is SDM mode in allthe PDN connections of the UE 100. FIG. 9 is a diagram illustrating aprocess of asking, by an MME 903, the PGW2 906 to check whethercorresponding UE is sending and receiving normal data when the MME 903receives information about the mode change of UE 901 from the PGW1 905with respect to the UE 901 having two PDN connections with a PGW1 905and a PGW2 906 according to an embodiment.

Referring to FIG. 9, at operation 912, an eNB 902 and the MME 903already know that the UE 901 is in connected mode.

At operation 914, the MME 903 may receive information about a modechange from the PGW1 905.

At operation 916 and operation 918, the MME 903 may check that the UE901 has PDN connections with the PGW2 906 in addition to the PGW1 905,and may check whether the UE 901 is sending and receiving normal data bysending a Normal Data Check Request message, that is, a GTP-C messageaccording to an embodiment, to the PGW2 906.

At operation 920, the PGW2 906 checks whether normal data is transmittedand receiving. As described above, the detection is possible through theTDF for detecting packets transmitted and received by the PGW2 906 orthe PGW2 906.

At operation 922 and operation 924, the PGW2 906 provides notificationthat the UE 901 is not sending and receiving normal data by sending aNormal Data Check Response message, that is, a GTP-C message accordingto an embodiment.

At operation 926, the MME 903 may determine a mode change based on theinformation received at operation 924.

At operation 928, the MME 903 may notify the eNB 902 of a mode change bysending a Mode Change Request, that is, an S1-AP message according to anembodiment.

At operation 930, the eNB 902 may perform a connected mode configurationbased on information about the mode change received at operation 928.

At operation 932, the eNB 902 may send information about mode configuredat operation 930 to the UE 901 through an RRC connection reconfigurationmessage.

At operation 934, the UE 901 sends an RRC connection reconfigurationcomplete message to the eNB 902.

At operation 936, the eNB 902 may send a Mode change response message,that is, an S1-AP message according to an embodiment, to the MME 903.

The UE 901 according to an embodiment may shift to idle mode after thetransmission of the normal data is completed. If the UE 902 is inconnected mode, the eNB 902 shifts the UE 902 to idle mode using anexisting method of shifting the state of the UE 901. That is, an S1bearer is released. In accordance with another embodiment, when an SDMinactivity timer or existing inactivity timer in connected mode expires,the eNB 902 may shift the UE 902 to idle mode. A timer applied when theUE 902 shifts to idle mode may be determined by a service provider.

A process of UE shifting from idle mode to SDM mode or connected mode isdescribed below.

If the UE 100 in idle mode attempts to send and receive data, the UE 100sends a Service Request message in order to establish radio connectionand core network connection.

The transmission of the service request complies with an existingstandard process. A network that has received the service request fromthe UE 100 configures the UE in SDM mode like in a method of determiningmode of the UE 100 in the Attach process.

If the UE 100 that has sent the service request wants to send smalldata, the UE 100 performs data transmission in configured SDM mode. Ifthe UE 100 wants to send normal data, the UE may shift to connected modeby additionally using the methods proposed by FIGS. 5A, 5B, 6, 7, and 8.

FIG. 10 is a diagram illustrating that when UE 1001 in idle mode sends aservice request in order to send data, the UE 1001 is configured in SDMmode according to an embodiment.

Referring to FIG. 10, a mode decision may be made by an MME 1003 or aneNB 1002. If the MME 1003 makes a mode decision, Alt1 methods 1018 and1036 of FIG. 10 are used. If the eNB 1002 makes a mode decision, Alt2methods 1024 and 1040 of FIG. 10 are used.

At operation 1012, the UE 1001 is in idle mode.

At operation 1014, the UE sends a Service Request message to the eNB1002.

At operation 1016, the eNB 1002 sends a service request to the MME 1003based on the message received at operation 1014.

Alt1) 1018, at operation 1020, the MME determines whether or not toconfigure the corresponding UE in SDM mode based on UE context.

At operation 1022, the MME 1003 may notify the eNB 1002 that the UE 1001is in SDM mode through an Initial Context Setup Request/Attach Acceptmessage. Information that provides such notification to the eNB 1002 maybe included in the Initial Context Setup Request/Attach Accept messageas a new parameter, or may be included as part of the subscription dataof the UE 1001. SDM mode indicative in FIG. 10 may include both theaforementioned two methods.

Alt2) 1024, at operation 1026, the MME 1003 sends the Initial ContextSetup Request/Attach Accept message to the eNB 1002.

At operation 1028, the eNB 1002 determines whether or not to configurethe UE 1001 in SDM mode depending on the context of the UE 1001.

At operation 1030, the eNB 1002 may perform a mode configuration basedon received SDM mode information.

At operation 1032, the eNB 1002 may send information about modeconfigured at operation 1030 to the UE 1001 through an RRC connectionreconfiguration message.

At operation 1034, the UE 1001 may send an RRC connectionreconfiguration complete message to the eNB 1002 based on the receivedRRC connection reconfiguration message.

Alt1) 1036, at operation 1038, the eNB 1002 may send an Initial contextSetup Complete message to the MME 1003.

Alt2) 1040, at operation 1042, the eNB 1002 may send the Initial contextSetup Complete message, including information that provides notificationthat the UE 1001 has been configured in SDM mode, to the MME 1003.

At operation 1044, the configuration of the UE 1001 in SDM mode iscompleted in the eNB 1002 and the MME 1003.

At operation 1046, the MME 1003 may notify an SGW 1004 that a modechange has occurred in the UE 1001.

The information may be included in a Modify Bearer Request message as anew parameter, or is possible by changing a value within an existingparameter. SDM mode indicative in FIG. 10 includes both theaforementioned two methods.

At operation 1050, the SGW 1004 sends the mode change information,received at operation 1046, to a PGW 1005. The mode change informationmay be transmitted to the PGW 1005 through a Modify Bearer Request or anew message.

In the case where the PGW 1005 does not always perform detection, butperforms detection only for some time or in a specific case, that is, inthe case where a triggering point at which detection is started isrequired, if the PGW is notified of a mode change, such notification maybecome a triggering point at which detection is started. For thisreason, an embodiment proposes a process of operation 1050. FIG. 13 is adiagram illustrating the flow of signals for controlling an RRCconnection time according to an embodiment.

Referring to FIG. 13, an embodiment proposes a method for moreeffectively controlling an RRC connection time. In an embodiment, thetransmission and reception of signals may be present between UE 1302, anRAN 1304, and an MME 1306.

At operation 1310, a node of the RAN 1304 may set the initial value ofan inactivity timer by taking into consideration one or more of thecharacteristics of a user and the characteristics of a serviceapplication being used by the user.

At operation 1315, the node of the RAN 1304 may determine whether anoperation related to the UE 1302 is not performed while the timecorresponding to the initial value of the inactivity timer elapses. Ifan operation related to the UE 1302 is not performed while the timecorresponding to the initial value of the inactivity timer elapses, thenode of the RAN 1304 may release one or more of connection with a corenetwork and connection with the UE 1302 at operation 1320 and operation1325. If not, the node of the RAN 1304 may perform a predeterminedoperation.

The core network may include the MME 1306, and the release of connectionwith the core network may be performed using one or more of methods ofdeleting an S1 release request and deleting S1-AP connection.

Furthermore, the release of connection with the UE 1302 may be performedusing one or more of methods of deleting RRC release and RRC connection.

In an embodiment, a method of setting, by the node of the RAN 1304, theinitial value of the inactivity timer by taking into consideration oneor more of the characteristics of a user and the characteristics of aservice application may be performed using one or more of methods ofdirectly receiving the initial value from the UE 1302, receiving theinitial value through subscription information, and receiving theinitial value determined by a PCC by taking into consideration thecharacteristics of traffic and a service application.

FIG. 14 is a diagram illustrating a method of setting an inactivity timebetween UE and a node of an RAN according to an embodiment.

Referring to FIG. 14, in an embodiment, the UE 1402 may directlytransfer an inactivity time to the node of the RAN 1404.

At operation 1410, the UE 1410 may determine a proper inactivity time bytaking into consideration one or more of information configured in theUE 1410, preference input by the user of the UE 1410, and thecharacteristics of application service now being executed.

At operation 1415, the UE 1402 may send the determined inactivity timeto the node of the RAN 1404. A method of transferring the determinedinactivity time may be performed using a method including one or more ofmethods of generating RRC connection using an RRC request message, usingan RRC request message that requests already established RRC connectionto be modified, and using one field of a MAC Control Element (CE).

At operation 1420, the node of the RAN 1404 may set the initial value ofan inactivity timer based on the inactivity time received at operation1415. Furthermore, according to an embodiment, the operation describedwith reference to FIG. 13 may be performed in subsequent operations.

FIG. 15 is a diagram illustrating a method of setting an inactivity timebetween UE and a node of an RAN according to another embodiment.

Referring to FIG. 15, the UE 1502 may request an inactivity time fromthe node of a core network. The node of the core network may configurethe node of the RAN 1504 based on the request. In an embodiment, thenode of the core network may include an MME 1506.

At operation 1510, the UE 1502 may determine a proper inactivity time bytaking into consideration one or more of information configured in theUE 1502, preference input by a user, and the characteristics ofapplication service now being executed.

At operation 1515, the UE 1502 may send information, including thedetermined inactivity time, to the node (e.g., the MME 1506) of the corenetwork. A method of transferring the information including thedetermined inactivity time to the node of the core network may includetransferring one or more messages of an initial NAS message, an attachrequest, a TAU request, and an RAU request.

At operation 1520, the node of the core network may store the inactivitytime received at operation 1515. According to an embodiment, the node ofthe core network may store the inactivity time in the form of one ofpieces of user information.

At operation 1525, the node of the core network may transfer theinactivity time to the node of the RAN 1504. According to an embodiment,when establishing connection with the UE 1502, the node of the corenetwork may send the inactivity time to an eNB (a node of the RAN 504)using an S1-AP message (e.g., an initial context setup request). Thenode of the core network may include the inactivity time in the S1-APmessage as one of pieces of information about the UE 1502.

At operation 1530, the node of the RAN 1504 may set the initial value ofan inactivity timer for the UE 1502 based on the received inactivitytime. Furthermore, according to an embodiment, the operation of FIG. 13may be subsequently performed.

FIG. 16 is a diagram illustrating a method of setting an inactivity timebetween a node of a core network and a node of an RAN according to anembodiment.

Referring to FIG. 16, according to an embodiment, the inactivity time ofUE 1602 may be stored as one of pieces of subscription information, andmay be then used.

A service provider may store the inactivity time of the UE in asubscription information database. The inactivity time of the UE may bestored as one of pieces of subscription information about the user ofthe UE. Furthermore, the subscription information database may includean HSS 1606.

At operation 1610, the HSS 1606 may transfer the inactivity time to thenode of the core network together with the subscription information. Thenode of the core network may include an MME 1604.

At operation 1615, the node of the core network may store the receivedinactivity time.

At operation 1620, the node of the core network may transfer theinactivity time to a node of the RAN 1602. According to an embodiment,the core network may send the inactivity time to the node of the RAN1602 when connection is established between the UE and the node of theRAN 1602. In this case, the value of the inactivity time may be storedaccording to each Access Point Name (APN), and may be transferred to thenode of the core network according to each APN.

In an embodiment, the subscription information database (HSS) 1606 mayinclude the inactivity time, stored as one of the pieces of subscriptioninformation, in an updating location ack message or an insertsubscription data message, and may transfer the inactivity time to thenode of the core network. The node (an MME 1604) of the core network maystore the inactivity time, may include the stored inactivity time in anS1-AP message (e.g., an initial context setup request), and may transferthe inactivity time when connection with the UE is established. The nodeof the RAN 1602 that has received information including the inactivitytime may set the initial value of an inactivity timer for the UE usingthe received inactivity time.

FIG. 17 is a diagram illustrating a method of setting an inactivitytimer by taking into consideration the traffic characteristic of aservice application of UE according to an embodiment.

Referring to FIG. 17, if the traffic of a variety of types of serviceapplications is being transmitted to UE, an inactivity timer may be setby taking into consideration the traffic characteristics of the varietyof types of service applications.

At operation 1710, a PCRF 1705 may determine an inactivity time bytaking into consideration the characteristics of a variety of kinds ofservice applications of UE.

At operation 1715, the PCRF 1705 may send information, including thedetermined inactivity time, to a PGW 1704. According to an embodiment,the PCRF 1705 may transfer the information, including the determinedinactivity time, to the PGW 1704 through PCC rule provisioning.

At operation 1720, the PGW 1704 may send the received information,including the inactivity time, to an SGW 1703. According to anembodiment, the PGW 1704 may transfer the received information,including the inactivity time, to the SGW 1703 through a GTP-c message.

At operation 1725, the SGW 1703 may send the received information,including the inactivity time, to a core network. According to anembodiment, the SGW 1703 may transfer the received information,including the inactivity time, to the core network through the GTP-cmessage. The core network may include an MME 1702.

In an embodiment, the value of the inactivity time may be set andtransferred according to each UE, each PDN connection (or APN), and eachEPS bearer.

At operation 1730, the node (MME 1702) of the core network may store thereceived inactivity time.

At operation 1735, the core network may send the information, includingthe inactivity time, to the RAN 1701. According to an embodiment, whenconnection with UE is established, the core network may include thestored inactivity time in an S1-AP message (e.g., an initial contextsetup request), and may send the inactivity time to a node of the RAN1701.

At operation 1740, the node of the RAN 1740 may set the initial value ofthe inactivity timer of the UE based on the received inactivity time.

Those skilled in the art to which the present disclosure pertains willappreciate that the present disclosure may be implemented in otherdetailed forms without departing from the technical spirit or essentialcharacteristics of the present disclosure. Accordingly, theaforementioned embodiments should be construed as being onlyillustrative, but should not be construed as being restrictive from allaspects. The scope of the present disclosure is defined by the followingclaims rather than the detailed description, and the meanings and scopeof the claims and all changes or modified forms derived from theirequivalents should be construed as falling within the scope of thepresent disclosure.

Meanwhile, preferred embodiments of the present disclosure disclosed inthis specification and drawings and specific terms used therein areillustrated to present only specific examples in order to clarify thetechnical contents of the present disclosure and help understanding ofthe present disclosure, but are not intended to limit the scope of thepresent disclosure. It will be evident to those skilled in the art thatvarious implementations based on the technical spirit of the presentdisclosure are possible in addition to the disclosed embodiments.

What is claimed is:
 1. A method performed by a network entity in awireless communication system, the method comprising: obtainingsubscription information associated with a terminal; identifyinginformation on a mobility of the terminal and information on an activityperiod based on the subscription information; obtaining assistanceinformation including the information on the mobility of the terminaland the information on the activity period; and transmitting, to a basestation, a message including the assistance information that is used todetermine a radio resource control (RRC) connection time for theterminal.
 2. The method of claim 1, wherein the assistance informationis further used to determine a state transition of the terminal.
 3. Themethod of claim 1, wherein the information on the mobility of theterminal indicates whether the terminal is to be stationary or mobile.4. The method of claim 1, wherein the message includes an initialcontext setup request message.
 5. A method performed by a base stationin a wireless communication system, the method comprising: receiving,from a network entity, a message including assistance information, theassistance information including information on a mobility of a terminaland information on an activity period; and identifying a radio resourcecontrol (RRC) connection time for the terminal based on the assistanceinformation.
 6. The method of claim 5, wherein subscription informationassociated with the terminal is used to identify the information on themobility of the terminal and the information on the activity period, andwherein the assistance information is further used to determine a statetransition of the terminal.
 7. The method of claim 5, wherein theinformation on the mobility of the terminal indicates whether theterminal is to be stationary or mobile.
 8. The method of claim 5,wherein the message includes an initial context setup request message.9. A network entity in a wireless communication system, the networkentity comprising: a transceiver; and a controller coupled with thetransceiver configured to: obtain subscription information associatedwith a terminal, identify information on a mobility of the terminal andinformation on an activity period based on the subscription information,obtain assistance information including the information on the mobilityof the terminal and the information on the activity period, andtransmit, to a base station, a message including the assistanceinformation that is used to determine a radio resource control (RRC)connection time for the terminal.
 10. The network entity of claim 9,wherein the assistance information is further used to determine a statetransition of the terminal.
 11. The network entity of claim 9, whereinthe information on the mobility of the terminal indicates whether theterminal is to be stationary or mobile.
 12. The network entity of claim9, wherein the message includes an initial context setup requestmessage.
 13. A base station in a wireless communication system, the basestation comprising: a transceiver; and a controller coupled with thetransceiver and configured to: receive, from a network entity, a messageincluding assistance information, the assistance information includinginformation on a mobility of a terminal and information on an activityperiod, and identify a radio resource control (RRC) connection time forthe terminal based on the assistance information.
 14. The base stationof claim 13, wherein subscription information associated with theterminal is used to identify the information on the mobility of theterminal and the information on the activity period, and wherein theassistance information is further used to determine a state transitionof the terminal.
 15. The base station of claim 13, wherein theinformation on the mobility of the terminal indicates whether theterminal is to be stationary or mobile.
 16. The base station of claim13, wherein the message includes an initial context setup requestmessage.